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As nanomaterials have a high surface-to-volume ratio, they have very specific features and therefore can be employed in a variety of applications. The development of electrochemical sensors based on novel nanocatalysts for detecting hazardous compounds is a primary concern. In the present work, we have proposed a novel synthesis protocol for a MoS 2 sphere-combined sulfur-doped Ti 3 C 2 MXene nanocatalyst (MoS 2 /S-Ti 3 C 2 ) and evaluated its electrochemical sensing performance. The structural characterization of this novel nanocatalyst revealed that it was successfully synthesized using a hydrothermal process. In addition, the electrochemical activity of different quantities of the MoS 2 /S-Ti 3 C 2 nanocatalyst loaded onto a laser-induced graphene electrode (LGE) was investigated, and it was discovered that 8 μL of MoS 2 /S-Ti 3 C 2 has the highest electrochemical activity. The as-fabricated MoS 2 /S-Ti 3 C 2 /LGE was used as a novel electrochemical sensing medium for the hazardous aristolochic acid (AA) and roxarsone (ROX) detection. Interestingly, the proposed MoS 2 /S-Ti 3 C 2 /LGE sensor exhibited a high sensitivity of 69.955 and 32.488 μA μM −1 cm −2 for AA and 56.972 and 19.688 μA μM −1 cm −2 for ROX with a detection limit of 1.65 and 2.31 nM, respectively, in the concentration range of 0.01−875.01 μM. In addition, the influence of few selected potential interferences does not show a significant effect on the sensing of AA and ROX, making it the best sensing device for practicability analysis. Moreover, the practical application of the fabricated sensor was successfully evaluated in asarum sieboldii, human urine, and human blood serum samples with a recovery rate of 97.00−99.00%.

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Acacia auriculiformis seedpod biomass-derived activated biocarbon was generated by carbonization followed by chemical activation using KOH. The formation of the biocarbon having hierarchical porous, pyrrolic nitrogen and high surface area has been confirmed using material characterization techniques. Then, sodium-ion energy storage performances of the biocarbon was examined in the half-cell that resulted in 255 mAh g −1 as the discharge capacity at 0.1 C rate with passable rate capability and cycling stability. Further, the activated biocarbon was also tested as the electrode material for symmetric sodium-ion ultracapacitors in aqueous and non-aqueous electrolytes. The aqueous ultracapacitor exhibited an energy density of nearly 62 Wh kg −1 , while the nonaqueous ultracapacitor resulted in a high specific energy of 138 Wh kg −1 . When assembled in a laboratory prototype pouch cell, the activated biocarbon electrode showed a high specific energy (150 Wh kg −1 ) at a specific power of 1495 W kg −1 . The disordered porous nitrogen-containing biocarbon associated with a high surface area leads to efficient sodium-ion storage as well as double-layer capacitance. The fabricated laboratory prototype sodium-ion ultracapacitor was practically tested to power a conventional red light-emitting diode for about 20 min on a single charge.